The present invention pertains to electrical connectors generally, and to electrical plugs and socket receptacles in particular. This invention provides a pin-piercing connector that may be installed on most commonly-used flat household electrical cords without tools and with no need to slit or strip the cords. Internally, the connector is adapted to enable its use with most common sizes of flat household insulated electrical conducting cord having two electrical conducting elements, such as cords in the size range of SPT-1 18 to SPT-2 18 to SPT-2 16 and HPN wires. The design of the channel inside the housing where the cord is inserted allows use of various cord sizes because the force of the piercing prongs as they penetrate the cord's insulation distorts and compresses the insulation within the channel so that the prongs are aligned with the internal electrical conducting wire elements despite variations in the spacing of those wires due to differing insulation thickness. Furthermore, the connector may be installed quickly, safely, and securely without the use of tools.
Prior art connectors, such as those disclosed in U.S. Pat. Nos. 3,408,616 and 4,243,287, suffer from the disability of being usable only with one size of conductor cord. Most prior art connectors also require the use of tools for installation. Although some earlier connectors, such as that in U.S. Pat. No. 3,816,819, have channels large enough to accept various cord sizes, none provides for alignment of the piercing prongs with the internal conductor elements as insulation thickness and conductor element spacing varies without either slitting or stripping the cords. Without such alignment, there is no assurance of a secure contact between the wire and the piercing prongs, which contact is essential to the function and safety of an electrical connector.